#include <bits/stdc++.h>
#include <cstdio>
#include <string>

using namespace std;

#define INF 100000000
#define YJ 1145141919
#define INF_INT_MAX 2147483647
#define INF_LL_MAX 9223372036854775807
#define EPS 1e-10
#define MOD 1000000007
#define Pi acos(-1)
#define LL long long
#define ULL unsigned long long
#define LD long double

class Node {
public:
    Node(unsigned long long int lIndex = startLeftIndex, unsigned long long int rIndex = endRightIndex, LL v = unitValue) : leftIndex(lIndex), rightIndex(rIndex), value(v) {

    }

    Node operator + (const Node& monoid) const {
        return Node(startLeftIndex, endRightIndex, this->getValue() + monoid.getValue());
    }

    static Node unit() {
        return Node(unitValue);
    }

    void setValue(LL l) {
        this->value = l;
    }

    LL getValue() const {
        return this->value;
    }

    
    
    
    

    pair<LL, LL> getIndexRange() {
        return make_pair(leftIndex, rightIndex);
    }

    bool isLeafNode() {
        auto it = getIndexRange();
        return it.second - it.first <= 1;
    }

    //値の設定
    void setValue(unsigned long long int index, LL value) {
        auto indexRange = getIndexRange();
        unsigned long long int leftIndex = indexRange.first, midIndex = (indexRange.first + indexRange.second)/2, rightIndex = indexRange.second;
        if(isLeafNode()) {
            if(leftIndex <= index && index < rightIndex) {
                setValue(value);
            } 
            return;
        }

        if(!left_child) {
            left_child = unique_ptr<Node>(new Node(leftIndex, midIndex));
        }
        if(!right_child) {
            right_child = unique_ptr<Node>(new Node(midIndex, rightIndex));
        }

        if(leftIndex <= index && index < midIndex) {
            left_child->setValue(index, value);
        } else {
            right_child->setValue(index, value);
        }

        //戻るときに値を更新していく
        Node lNode, rNode; lNode.setValue(left_child->getValue()); rNode.setValue(right_child->getValue());
        setValue((lNode + rNode).getValue());
    }

    LL query(unsigned long long int l, unsigned long long int r) {
        auto indexRange = getIndexRange();
        if(l <= indexRange.first && indexRange.second <= r) {
            return getValue();
        } else if(indexRange.second <= l || r <= indexRange.first) {
            return Node::unit().getValue();
        } else {
            LL ll = Node::unit().getValue(), rr = Node::unit().getValue();
            if(left_child) {
                ll = left_child->query(l, r);
            }
            if(right_child) {
                rr = right_child->query(l, r);
            }
            Node lNode, rNode;
            lNode.setValue(ll); rNode.setValue(rr);
            return (lNode + rNode).getValue();
        }
    }

private:
    LL value;
    static const LL unitValue = 0;
    static const LL startLeftIndex = 0, endRightIndex = 1145141919810;

    unique_ptr<Node> left_child, right_child;
    unsigned long long int leftIndex, rightIndex;
};

template <class T>
class SegmentTree {
public:
    SegmentTree() {
        root = unique_ptr<Node>(new Node());
    }

    void setValue(unsigned long long int index, LL value) {
        root->setValue(index, value);
    }

    LL query(unsigned long long int l, unsigned long long int r) {
        return root->query(l, r);
    }
private:
    unique_ptr<T> root;
};

#define int long long

typedef pair<LL, int> Key;
typedef int Value;

struct Treap{
  Key key; //キー
  Value value; //値
  Treap *ch[2]; //左、右
  int pri; //優先度 大きい方が上に来るようにする
  int cnt; //部分木のサイズ
  int sum; //部分木の値の和

  Treap(const Key &key, const Value &value) : key(key), value(value), pri(rand()), cnt(1), sum(value) {
    ch[0] = ch[1] = NULL;
  }

};

//部分木のサイズを取得
int countTreap(Treap *t){return !t ? 0 : t->cnt;}

//部分木の和を取得
int sumTreap(Treap *t){return !t ? 0 : t->sum;}

//部分木のサイズや和は部分木に何かしらの操作を加えるた度に更新を行って
//整合性を保つ
Treap *updateTreap(Treap *t){
  t->cnt = countTreap(t->ch[0]) + countTreap(t->ch[1]) + 1;
  t->sum = sumTreap(t->ch[0]) + sumTreap(t->ch[1]) + t->value;
  return t;
}

//b:0 左回転　1 右回転
Treap *rotateTreap(Treap *t, int b){
  Treap *s = t->ch[1-b];
  t->ch[1-b] = s->ch[b];
  s->ch[b] = t;
  updateTreap(t); updateTreap(s);
  return s;
}

//tが根となっている木に(key, value)を挿入
Treap *insertTreap(Treap *t, const Key &key, const Value &value){
  if(!t) return new Treap(key, value);
  else if(key == t->key) return t;
  int b = !(key < t->key);
  t->ch[b] = insertTreap(t->ch[b], key, value);
  updateTreap(t);
  //優先度が大きい方が上に来るようにする
  if(t->pri < t->ch[b]->pri)
    t = rotateTreap(t, 1-b);
  return t;
}

//key値のものを取り出す
Treap *findTreap(Treap *t, const Key &key){
  return !t || key == t->key ? t : findTreap(t->ch[t->key < key], key);
}

//index(0-index)番目の要素を参照する
Treap *findIndexTreap(Treap *t, int index = 0){

  //現在指しているポインタがNULLか、indexが現在の部分木のサイズ外を指している場合
  if(!t || t->cnt <= index) return NULL;

  if(t->ch[0]){
    if(index < t->ch[0]->cnt){
      return findIndexTreap(t->ch[0], index);
    }
    else{
      index = index - (t->ch[0]->cnt);
      if(index == 0)
	return t;
      else
	return findIndexTreap(t->ch[1], index-1);
    }
  }
  else if(t->ch[1]){
    if(index == 0)
      return t;
    else
      return findIndexTreap(t->ch[1], index - 1);
  }
  else{
    if(index == 0)
      return t;
    else
      return NULL;
  }

}

//key値のノードを削除する
Treap *eraseTreap(Treap *t, const Key &key){
  if(!t)
    return NULL;
  if(key == t->key){
    if(!t->ch[0] && !t->ch[1]){
      //tの内容を初期化する
      return NULL;
    }
    else if(!t->ch[0])
      t = rotateTreap(t, 0);
    else if(!t->ch[1])
      t = rotateTreap(t, 1);
    else
      t = rotateTreap(t, !(t->ch[0]->pri < t->ch[1]->pri));
    t = eraseTreap(t, key);
  }
  else{
    int b = !(key < t->key);
    t->ch[b] = eraseTreap(t->ch[b], key);
  }
  updateTreap(t);
  return t;
}



const int MAX_N = 100005;
const int MAX_K = 100005;

int N, K;
int A[MAX_N];

SegmentTree<Node> segmentTree;
SegmentTree<Node> segmentTreeCount;

signed main()
{
    Treap *root = NULL;
    cin >> N >> K;
    for(int i = 0; i < N; i++) {
        cin >> A[i];
    }

    int sum = 0;
    int ans = 1145141919810364;
    for(int i = 0; i < N; i++) {
        sum += A[i];
        root = insertTreap(root, Key(A[i], i), A[i]);
        segmentTree.setValue(A[i], segmentTree.query(A[i], A[i]+1) + A[i]);
        segmentTreeCount.setValue(A[i], segmentTreeCount.query(A[i], A[i]+1)+1);

        if(countTreap(root) == K) {
            Treap *t = findIndexTreap(root, (K-1)/2);
            int mid = t->value;

            int L = 0, R = 0;
            int lCount = segmentTreeCount.query(0, mid);
            int rCount = segmentTreeCount.query(mid+1, 1e9+7);
            L = mid*lCount - segmentTree.query(0, mid);
            R = segmentTree.query(mid+1, 1e9+7) - mid*rCount;
            
            // cerr << i << " " << L << " " << R << endl;
            // cerr << lCount << " " << rCount << " " << mid << endl;
            // cerr << segmentTree.query(0, mid) << " " << segmentTree.query(mid+1, 1e9+7) << endl;
            // cerr << endl;

            ans = min(ans, L+R);

            // cerr << i << " " << mid << " " << sum << endl;

            sum -= A[i-K+1];
            root = eraseTreap(root, Key(A[i-K+1], i-K+1));

            int AA = A[i-K+1];
            segmentTree.setValue(AA, segmentTree.query(AA,AA+1) - AA);
            segmentTreeCount.setValue(AA, segmentTreeCount.query(AA, AA+1)-1);
        }
    }

    cout << ans << endl;

    return 0;
}